apache-api/5771: Comparison of encrypted password improperly fails

[Rob Sims <ro...@hpesjro.fc.hp.com>]

>Number:         5771
>Category:       apache-api
>Synopsis:       Comparison of encrypted password improperly fails
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Wed Feb 16 15:20:01 PST 2000
>Closed-Date:
>Last-Modified:
>Originator:     robsims@hpesjro.fc.hp.com
>Release:        1.3.11
>Organization:
apache
>Environment:
HP-UX hpesjro B.10.20 A 9000/782 2002236203 two-user license
>Description:
Some operating systems append password rules (expiration, last time of change)
within the password field, so that the field contains 2 bytes salt, 11 bytes 
password, a comma, and some (2-4 in my case) rules bytes.

ap_validate_password in src/ap/ap_checkpass.c won't validate a password in 
this case.

Further warning from the man page:
 WARNINGS
      The return value for crypt() points to static data whose content is
      overwritten by each call.  crypt(), setkey(), and encrypt() are unsafe
      in multi-thread applications.  crypt_r(), setkey_r(), and encrypt_r()
      are MT-Safe and should be used instead.
>How-To-Repeat:
Set up a module that uses a password or NIS services on a machine that supports
password rules.
>Fix:
Change the (almost) last line in ap_checkpass.c from:
return (strcmp(sample, hash) == 0) ? NULL : "password mismatch";
To:
return (strncmp(sample, hash, strlen(sample)) == 0) ? NULL : "password mismatch";
Or:
return (strncmp(sample, hash, 13) == 0) ? NULL : "password mismatch";

crypt seems to return a non-null string if hash is non-null.
>Release-Note:
>Audit-Trail:
>Unformatted:
 [In order for any reply to be added to the PR database, you need]
 [to include <ap...@Apache.Org> in the Cc line and make sure the]
 [subject line starts with the report component and number, with ]
 [or without any 'Re:' prefixes (such as "general/1098:" or      ]
 ["Re: general/1098:").  If the subject doesn't match this       ]
 [pattern, your message will be misfiled and ignored.  The       ]
 ["apbugs" address is not added to the Cc line of messages from  ]
 [the database automatically because of the potential for mail   ]
 [loops.  If you do not include this Cc, your reply may be ig-   ]
 [nored unless you are responding to an explicit request from a  ]
 [developer.  Reply only with text; DO NOT SEND ATTACHMENTS!     ]